What car/driving related urban myths have you heard of?

What car/driving related urban myths have you heard of?

Author
Discussion

SBN

1,025 posts

154 months

Saturday 5th November 2011
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A dump valve doesnt make my car sound like a bus wink

AmitG

3,312 posts

162 months

Saturday 5th November 2011
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GC8 said:
The source was that a component within the VTEC system hadnt ever failed under warranty. This was phrased in such a way by Honda, as to give a grander impression.

This boast has since been embraced by the sort of petrolhead / PistonHead wally who thinks that flashing his headlamps at a radar controlled traffic signal 'makes it change' - and its slowly morphed into 'a VTEC (engine) hasnt ever failed', and is now repeated knowledgeably on forums...
I seem to remember the Honda claim being "we have never had to rebuild or replace a VTEC engine under warranty".


cymtriks

4,560 posts

247 months

Saturday 5th November 2011
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Nick3point2 said:
cymtriks said:
Anti lock brakes work by stopping wheels from skidding.

No they don't.

They work by keeping the wheels as close as possible to their maximum level of grip. Tyres grip more and more as skidding builds up and then start to lose grip. As the optimum grip speed, which involves some rolling and some skidding, is very difficult to maintain in practice the solution is to let the skidd happen and back off then let the skid happen and back off. This keeps moving the wheel over that critical point of maximum grip.

So actually ABS is trying to hold as close as possible to a controlled skid and roll combination.
No, sorry that's wrong. ABS keeps optimum slip, which is a misnomer. Not skid. Slip is how a measure of how distorted the contact the contact patch is due to longitudinal or latitudinal forces put through the tyre.

The true urban myth surrounding ABS is that "ABS doesn't make you stop any quicker, it just stops you losing control".

Which is where your comments come in. Tyres grip better the more heavily distorted the contact patch it, to a point, before they rapidly lose grip (lock up). ABS keeps the tyres in this 'maximumly distorted' point.
Semantics over the words "skid" and "slip". smile

Zwoelf

25,867 posts

208 months

Saturday 5th November 2011
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GC8 said:
The source was that a component within the VTEC system hadnt ever failed under warranty. This was phrased in such a way by Honda, as to give a grander impression.

This boast has since been embraced by the sort of petrolhead / PistonHead wally who thinks that flashing his headlamps at a radar controlled traffic signal 'makes it change' - and its slowly morphed into 'a VTEC (engine) hasnt ever failed', and is now repeated knowledgeably on forums...
I recall it being asserted by one Mr. J. Clarkson of Chipping Norton and the only other engine with a similar warranty record was the Mercedes M120 V12.

pimpin gimp

3,285 posts

202 months

Saturday 5th November 2011
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I find the easiest way to get traffic lights is to stop, put the parking brake on and engage neutral. I can sit as long as I want with the foot brake on and it'll stay red for eternity, but as soon as I'm securely stationary and in neutral the bugger goes green!

Ian974

2,955 posts

201 months

Saturday 5th November 2011
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If you buy a new car it wont ever break until it suddenly falls to bits at 3 years old

busta

4,504 posts

235 months

Saturday 5th November 2011
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Ian974 said:
If you buy a new car it wont ever break until it suddenly falls to bits at 3 years old
...and if you buy a 10 year old car it will break down ALL the time.

At 100,000 miles, every single part of the car is on it's 'last legs' and it'll cost more than the price of a new car to fix it.

Having to do any repair on an old car is proof of this, where as a new car 'being at the garage for a couple of days because a fault light came on' is fine, because it comes back shiny. hehe

GC8

19,910 posts

192 months

Saturday 5th November 2011
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AmitG said:
I seem to remember the Honda claim being "we have never had to rebuild or replace a VTEC engine under warranty".
Im sure theyd like you to think that. I believe that their claim was that theyve never had a VTEC (actuator) fail under warranty.

mattnunn

14,041 posts

163 months

Saturday 5th November 2011
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In response to several recent threads on here, here aree some more urban/petrol head myths...

Cars make good investment opportunities, you just need to know which ones.

You don't need to service modern vehicles it's cheaper to run them until they explode.

It's a good idea to equip a fwd car with +200 Bhp

EDLT

15,421 posts

208 months

Saturday 5th November 2011
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martin84 said:
I have heard if you drive in reverse when you first start the engine you'll use 20 times more fuel for that 10 yards than going forwards but I don't know if anyones ever done tests to verify this.

Anybody fancy commuting backwards and reporting their mpg next week?
It's a myth started by people who think the engine spins backwards when you put it into reverse.

mattnunn

14,041 posts

163 months

Saturday 5th November 2011
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I believe Mr Ferris Bueller was responsible for that myth... And we know what happened next

otherman

2,194 posts

167 months

Saturday 5th November 2011
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trackerjack said:
What about the guy who claims a motorcycle gang lashed his car with chains and when he got home there was a chain with a finger stuck to it round his bumper, this one is always started with "a mate of mine".
Sounds like that mate just saw Mad Max I

cymtriks

4,560 posts

247 months

Saturday 5th November 2011
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otherman said:
trackerjack said:
What about the guy who claims a motorcycle gang lashed his car with chains and when he got home there was a chain with a finger stuck to it round his bumper, this one is always started with "a mate of mine".
Sounds like that mate just saw Mad Max I
Way older than Mad Max. That one was around when I was a kid. It used to be a gang of Rockers harrasing a man in a bubble car, he drove off and later found a finger stuck in the rear engine grill. You can guess from the "Rockers" and "Bubble car" just how old this story is.

66comanche

2,369 posts

161 months

Saturday 5th November 2011
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stuwalsh said:
Coasting in nuetral saves fuel. Maybe on a 1965 Morris Oxford but not on a modern ECU managed engine.
ears

Is that true? I remember during the cold weather last winter there was some discussion of how much fuel a car uses when idling and the consensus was very little indeed. I would have assumed that putting it into neutral and coasting at speed was effectively the same thing (approx 700rpm), as opposed to say being at 3000rpm in fifth with no pressure applied to the accelerator? Speaking as someone who sometimes coasts...

TheEnd

15,370 posts

190 months

Saturday 5th November 2011
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Police cars were all chipped, as an extra 5-10% more power made all the difference.


I like the hanging CD one, favoured by minicab drivers.
I'm still amazed none of the jet manufacturers have thought the best way of making a jet stealthy is a large reflector on the front.
The old double bluff...

"Comrade, we have an unusually large return showing moving in from 015 and 600kts"

"It's a trap!, turn all scanners south and scramble all jets!"

Cock Womble 7

29,908 posts

232 months

Saturday 5th November 2011
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I'm not sure if it's been mentioned, but I heard something about flashing your headlights at traffic lights to make them change to green?

DanielC4GP

2,792 posts

153 months

Saturday 5th November 2011
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66comanche said:
stuwalsh said:
Coasting in nuetral saves fuel. Maybe on a 1965 Morris Oxford but not on a modern ECU managed engine.
ears

Is that true? I remember during the cold weather last winter there was some discussion of how much fuel a car uses when idling and the consensus was very little indeed. I would have assumed that putting it into neutral and coasting at speed was effectively the same thing (approx 700rpm), as opposed to say being at 3000rpm in fifth with no pressure applied to the accelerator? Speaking as someone who sometimes coasts...
Modern engines don't use any fuel at all if the accelerator isn't applied whilst rolling down hill or slowing down whilst in gear. Hence why coasting actually uses more fuel as fuel is being used to keep the engine running.

mattnunn

14,041 posts

163 months

Saturday 5th November 2011
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DanielC4GP said:
Modern engines don't use any fuel at all if the accelerator isn't applied whilst rolling down hill or slowing down whilst in gear. Hence why coasting actually uses more fuel as fuel is being used to keep the engine running.
i'm no expert but i'm pretty sure engines stall when starved of fuel

Debaser

6,117 posts

263 months

Saturday 5th November 2011
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mattnunn said:
DanielC4GP said:
Modern engines don't use any fuel at all if the accelerator isn't applied whilst rolling down hill or slowing down whilst in gear. Hence why coasting actually uses more fuel as fuel is being used to keep the engine running.
i'm no expert but i'm pretty sure engines stall when starved of fuel
Not if it's still connected to the wheels...

Thankyou4calling

10,629 posts

175 months

Saturday 5th November 2011
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So are you saying that if you take your foot off the accelerator, the engine will continue to run but not use any fuel? If that's true then a miracle has occurred.